Adiponectin, Leptin, and Resistin Are Dysregulated in Patients Infected by SARS-CoV-2

Abstract

Obesity, through adipose tissue (AT) inflammation and dysregulation, represents a critical factor for COVID-19; here, we investigated whether serum levels of adiponectin, HMW oligomers, leptin, and resistin are modulated and/or correlated with clinical and biochemical parameters of severe COVID-19 patients. This study included 62 severe COVID-19 patients; 62 age and sex-matched healthy subjects were recruited as a control group. Anthropometric and biochemical parameters were obtained and compared. Adiponectin, HMW oligomers, leptin, and resistin were analyzed by ELISA. The adiponectin oligomerization state was visualized by Western blotting. When compared to healthy subjects, total adiponectin levels were statistically lower in severe COVID-19 while, in contrast, the levels of leptin and resistin were statistically higher. Interestingly, HMW adiponectin oligomers negatively correlated with leptin and were positively associated with LUS scores. Resistin showed a positive association with IL-6, IL-2R, and KL-6. Our data strongly support that adipose tissue might play a functional role in COVID-19. Although it needs to be confirmed in larger cohorts, adiponectin HMW oligomers might represent a laboratory resource to predict patient seriousness. Whether adipokines can be integrated as a potential additional tool in the evolving landscape of biomarkers for the COVID-19 disease is still a matter of debate. Other studies are needed to understand the molecular mechanisms behind adipokine’s involvement in COVID-19.

Adipokines as Diagnostic and Prognostic Markers for the Severity of COVID-19

“…In 62 COVID-19 patients whose symptom onset was less than 3 days before hospital admission, circulating leptin levels were elevated in comparison to 62 healthy controls. Although this adds to the reports pointing to elevated leptin levels being indicative of a SARS-CoV-2 infection; the implications of this study are limited due to the higher BMI of the COVID-19 patients, which may well explain higher serum leptin levels irrespective of the SARS-CoV-2 infection [74]. Hence, it remains to be clarified if circulating leptin levels are associated with BMI in SARS-CoV-2-infected patients.…”

“…Here, the high molecular weight adiponectin complexes, but not the total serum adiponectin amounts, correlated positively with the level of lung injury, as judged by the lung ultrasound score. A limitation of this study was the higher BMI of COVID-19 patients in this cohort, a feature, whose association with lower circulating adiponectin levels has been well-described [74,91]. Adiponectin was also found to be reduced in the plasma of severely ill COVID-19 patients in comparison to healthy controls and patients with mild symptoms.…”

“…On the other hand, serum leptin levels were not related to ARDS or outcome [108] and did not correlate with the lung ultrasound score [74]. In a group of 145 hospitalized patients, leptin levels were not related to intensive care requirement or patient outcome [69].…”

Adiponectin Increase in Patients Affected by Chronic Obstructive Pulmonary Disease with Overlap of Bronchiectasis

“…Recently, although still under investigation, IFN therapy has been proposed to prevent COPD exacerbations [ 42 ]. Therefore, the interplay between adipocytokines and pro-inflammatory mediators might play a central role both in acute exacerbation triggered by viral and bacterial pathogens [ 43 , 44 ].…”

Neutrophil degranulation, endothelial and metabolic dysfunction in unvaccinated long COVID patients

“…15 Potential candidates are a number of molecules involving neutrophil degranulation, [16][17][18] endothelial [19][20][21] and metabolic dysfunction (i.e. adipokines [22][23][24][25] ), but the ultimate role of such mediators is still unclear.…”